At San Diego Comic-Con on Friday, ET's Ashley Crossan caught up with the Guardians of the Galaxy Vol. 2 star, who offered praise to Jodie Whittaker's Doctor Who casting, making her the first female doctor in the BBC One program's long run.

"I'm so excited because so many people were like, 'It cant be a woman,'" said Gillan, who is best known for playing Amy Pond on the series from 2010 to 2013. "And I'm like, 'You're all insane, and of course she can.' And now we have one ... I'm completely delighted."

"First of all, if you ever watched Star Trek: Voyager, Captain Janeway came in -- the only female captain -- and absolutely nailed it, so we know that that can work," she pointed out. "And second of all, just relax, it's fine!"